Self-Healing and Self-Adhesion Conductive Hydrogels Reinforced by Carboxylated Carbon Nanotubes for High-Performance Wearable Strain Sensors

Hydrogels with good mechanical properties, self-adhesion, and self-healing properties show broad prospects in the fabrication of sensors. Herein, PAA/PVA-Al-cCNT hydrogels were constructed and fabricated based on the combination of hydrogen bond and metal coordination in this study. Due to the introduction of Al3+ and cCNTs, the prepared PAA/PVA-Al-cCNT hydrogels exhibited good mechanical properties (tensile strength of 179.7 kPa and elongation at break of 634%), good self-adhesion toward various substances including human skin, rubber, stone, metal, leaves, plastic, etc., great conductivity (1.69 S/m), and high self-healing efficiency (96% at 20 h). The hydrogels can be used to assemble sensors with wide response range and high sensitivity. Based on the self-healing ability, the self-healed hydrogel sensor could detect the human motion as the original one, which has great application potential in the field of flexible strain and pressure sensing.